title: Blood and ultrafiltrate dosage of citrate as a useful and routine tool during continuous venovenous haemodiafiltration in septic shock patients.
abstract: BACKGROUND
  Citrate anticoagulation is gaining popularity in renal replacement therapies (RRT) for critically ill patients. In order to study whether citrate accumulates in septic shock patients, we determined citrate in plasma and dialysate during continuous venovenous haemodiafiltration (CVVHDF).
  
  
  METHODS
  An automated routine determination of citrate was set up using a commercial kit (citrate lyase method). Twelve patients with septic shock on CVVHDF and citrate anticoagulation were studied ex vivo for citrate levels in systemic and circuit blood and in the ultrafiltrate (at 0, 0.5, 1, 3, 6, 9, 12, 24, 48 and 72 h).
  
  
  RESULTS
  In vitro blood studies showed a near unit correlation between the plasma measured and predicted citrate concentrations for an exclusive extracellular distribution of citrate. Median systemic arterial citratemias were 0.09 (0.06-0.12) mmol/L (Time 0) and 0.23 (0.18-0.31) mmol/L during treatment; median sieving coefficient for citrate was 0.95 (0.88-1.02) and did not change with different volumes of CVVHDF effluent (from 1350 to 5100 mL/h). Net citrate and calcium removal by filter significantly correlated with effluent volume (r = 0.85 and 0.78, respectively). Median citrate load entering in the patients' bloodstream was 13.60 (9.1-19.6, n = 68) mmol/h. Although cost analysis of the citrate test demonstrated a minimally increased daily cost (from 2.96 to 3.51€), saving costs could be potentially relevant with more extended use of citrate anticoagulation.
  
  
  CONCLUSIONS
  In septic shock patients with liver dysfunction citratemia is useful in guiding clinical application of RRT, where the citrate losses in the ultrafiltrate can be efficiently modulated by increasing the effluent volume.
authors.affiliation: Department of Medicine Area, Nephrology and Dialysis Unit, CTO Hospital, Turin, Italy. filippo.mariano@poste.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Mariano
authors.forename: Maurizio
authors.initials: M
authors.lastname: Morselli
authors.forename: Daniela
authors.initials: D
authors.lastname: Bergamo
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Hollo
authors.forename: Sandro
authors.initials: S
authors.lastname: Scella
authors.forename: Mariella
authors.initials: M
authors.lastname: Maio
authors.forename: Ciro
authors.initials: C
authors.lastname: Tetta
authors.forename: Ambrogio
authors.initials: A
authors.lastname: Dellavalle
authors.forename: Maurizio
authors.initials: M
authors.lastname: Stella
authors.forename: Giorgio
authors.initials: G
authors.lastname: Triolo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019343:Citric Acid / Q000032:analysis* / Q000097:blood; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D015312:Hemodialysis Solutions / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012772:Shock, Septic / Q000628:therapy*; D014680:Veins
chemical_list: D015312:Hemodialysis Solutions; D019343:Citric Acid